Try resetting the tools and/or preferences. To restore preferences quickly using a keyboard shortcut:
Press and hold Alt+Control+Shift (Windows) or Option+Command+Shift (Mac OS) as you start Photoshop. You are prompted to delete the current settings. The new preferences files are created the next time you start Photoshop. Note: Using the keyboard shortcut, preference files for custom shortcuts, workspaces, and color settings will also be reset to default.
If that doesn’t work, try updating or rolling back your graphics driver directly from the video card manufacturer’s site. If NVIDIA, do a clean installation of the latest Studio Driver (NOT the Game Driver)